Electrical circuit



May 11, 1948. J. R. LINDSAY 2,441,497

ELECTRICAL CIRCUIT I Original Filed Aug. 16, 1944 TRANSFORM ESE MOfiOESECONDARY. I w: mamas TEAN SFOEM ER SECONDARY /N\/EN7'OE -JAM ES ROBERTLIN DSAY,

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Patented May 11, 1948 ELECTRICAL CIRCUIT J ames Robert Lindsay,Arlington Heights, 111., as-

signor to The Jeffrey Company, a corporation of Ohio Originalapplication August 16, 1944, Serial No.

1945, Serial No. 605,547

4 Claims. 1

This invention relates to an electrical circuit, and an object of theinvention is to provide an electrical circuit including a vibratoryelectromagnetic motor energized with three-phase alternating current,one of the phases of which is reversely connected.

Another object of the invention is to provide an electrical circuit forenergizing a vibratory electromagnetic motor with mixed alternating anddirect current, in which the alternating current is supplied by athree-phase circuit, one of the coils of which is reversely connected.

A further object of the invention is to provide improved electromagneticmotor field construction which is energized from a three-phase source,one of the field coils being reversely connected.

Other objects of the invention will appear hereinafter, the novelfeatures and combinations being set forth in the appended claims.

In the accompanying drawings,

Fig. 1 is a wiring diagram of an electrical system employing three-phasecurrent to energize the windings of an electromagnetic motor, thephysical or structural relation of the motor windings, field andarmature being illustrated;

In Fig. 1 I have illustrated the motor windings in a manner to suggestthe phase relation of the alternating current flowing therethrough; and

Fig. 2 of the drawings shows a different electrical circuit energizing amotor winding.

This application is filed as a division of my application Serial No.549,738, filed August 16, 1944. Patent No. 2,419,686, dated April 29,1947, for an improvement in an Electrical circuit.

Referring first to Figs. 1 and 1 of the drawings, the transformersecondary of a three phase transformer is indicated generally at III andit constitutes three phase windings II, I2 and I3 connected in delta,the voltages therein being 120 degrees apart. Three phase conductorsdesignated I, 2 and 3 extend from the secondary winding III to threecoils I4, I5 and I6 which are wound on the field core I I of a vibratoryelectromagnetic motor having a vibratory armature I8. The windings I4,I5 and I 6 are so poled as to give relative instantaneous polarities asindicated by the letters NSN in Fig. 1 of the drawings. Since the twooutside poles are at the instant north and the center poles south, it isobvious that the flux through the center pole will be split between thetwo outside, and consequently it has preferably twice thecross-sectional area as suggested diagrammatically in Fig. 1 of thedrawings.

Furthermore, as suggested in Fig. 1 of the Divided and this applicationJuly 17,

drawings, the windings I4, I5 and I6 are so connected that the currentsin them are 60 degrees out of phase. In other words, winding I5 isreversely connected as compared with what it would normally be in athree phase star connection. Still further, the'number of turns on thewindings I4, I5 and I5 is selected so that windings I4,

I5 and I5 have the same number of D. C. ampere turns. To provide this,windings I4 and I6 have the same number of turns and winding I5 willhave essentially half their number of turns.

To provide mixed current operation, conductor 3 has connected therein asource of direct current I9 which is preferably of low voltage ascompared with the alternating current voltage. For example, it will be10 to 20 volts, where the alternating current voltage on a winding I I,I2 or I3, will be volts.

The direct current source I9 may be a battery, a direct currentgenerator, or a rectifier. The path of the direct current is indicatedby the arrows in Figs. 1 and 1 of the drawings. It is to be particularlynoted that all the direct current from the source I9 flows throughwinding I5, the direct current then splitting, one-half flowing betweenthe winding or coil I4, the other half between the winding or coil I 5.Return flow of the direct current also splits between the windings I Iand I2.

As is well known, this mixed current operation provides vibration of thearmature I8 toward and from the pole faces of the field core II at thefrequency of the alternating current in the secondary of transformerII]. This vibration is caused by the periodic attraction of thepulsating flux in field core I1 and armature I8 which is periodicallyreduced so that a spring bar or the like pulls the armature I8 away fromthe field core II. Such a motor with single phase winding is seen in thepatent to James A. Flint, No. 2,153,243, dated April 4, 1939. Ifstraight alternating current operation is desired, the source of directcurrent I9 is merely omitted and in this case the frequency of vibrationof the armature I8 will be twice the frequency of the alternatingcurrent.

In Fig. 2 of the drawings I have shown a system in which the transformersecondary 20 is connected in star rather than in delta; the motorwindings or coils I 4, I5 and I6 being connected the same as before. Inthis construction, where mixed current operation is desired, the sourceof direct current I5 is connected between the neutral point of thetransformer secondary 20 and the neutral point of the windings or coilsI4, I and I6 by way of conductor 2|.

The difference between the circuits of Figs. 1 and 2 requires adifferent winding of the coils of the motor for the two systems. Thatis, in

- the system of Fig. 1 the direct current in coil I5 splits betweencoils I4 and I6. Consequently, coil I5 has twice the direct currentamperage flow therethrough as compared with coils I4 and I6. In thesystem of Fig. 2 the direct current flow through the motor windings I4,I5 and I6 is the same since the direct current delivered by source I9merely splits three ways, as illustrated by the arrows in Fig. 2 of thedrawings.

To preserve the desired balance of D. C. ampere turns in the motorwinding in the system of Fig. 2, it is evident that each of the coilsI4, I5 and IE will have the same number of turns.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of the invention as defined by the claims hereto appended, and Itherefore wish not to be restricted to the precise construction hereindisclosed.

Having thus described and shown an embodiment of my invention, what Idesire to secure by Letters Patent of the United States is:

1. An electrical motor circuit including a source of three phasecurrent, a vibratory electrical motor energized therefrom including afield structure having pole faces and an armature mounted to vibratetoward and from said pole faces and be periodically attracted by theflux in said field structure, said field structure including three starconnected field coils, one energized from each phase, one of said coilsbeing reversely connected so the current therein is 60 degrees from thatin the others, and a source of direct current connected to energize allof said coils.

2. An electrical motor circuit including a source of three phasecurrent, and a vibratory electrical motor energized therefrom includinga field structure having pole faces and an armature mounted to vibratetoward and from said pole faces and be periodically attracted by theflux in said field structure, said field structure ineluding threestar-connected field coils, one energized from each phase, one of saidcoils being reversely connected so the current therein is degrees fromthat in the others.

3. An electrical circuit including a source of three phase current, avibratory electrical motor energized therefrom including three windings,one of said windings being reversely connected so the current therein is60 degrees from that in the others, and a source of direct currentconnected to said windings to flow through one of them and then splitand flow in parallel through the other two.

4. An electrical circuit including a source of three phase current, avibratory electrical motor energized therefrom including three windings,and a source of direct current connected to said windings to flowthrough one of them and then split and flow in parallel through theother two.

JAMES ROBERT LINDSAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 422,855 VanDepole Mar. 4, 1890429,729 Marvin June 10, 1890 1,647,147 Roller Nov. 1, 1927 2,153,243Flint Apr. 4, 1939 2,322,754 Undy June 29, 1943 2,419,686 Lindsay Apr.29, 1947 FOREIGN PATENTS Number Country Date 473,402 Germany Apr. 4,1939

